Three-axis flight simulation turntable for microwave anechoic chamber

Abstract

The present application relates to a kind of three-axis flight simulation rotary table for microwave darkroom, and the present application belongs to the technical field of guidance system semi-physical simulation equipment for radio frequency simulation.The rotary table adopts vertical structure, including base, yaw shaft system assembly, pitch shaft system assembly and rolling shaft system assembly, rolling shaft system is supported on pitch frame, pitch shaft system is supported on yaw frame, and frame assembly of three rotary degrees of freedom of inside, middle and outside is constituted, respectively simulate the roll, yaw and pitch attitude change of aircraft;Pitch movement is realized through parallel four-bar mechanism transmission, and yaw and rolling movement is realized by torque motor directly driving frame movement.Through the motion of each frame assembly, the three-dimensional attitude of aircraft in flight in the air can be simulated on the ground, and its working condition in flight state is tested.The present application has the characteristics of compact structure, high precision, large electromagnetic field static region, large load size, wide load weight range and the like.

Description

Technical Field

[0001] This invention relates to a three-axis flight simulation turntable for microwave anechoic chambers, which belongs to the technical field of hardware-in-the-loop simulation equipment for guidance systems used in radio frequency simulation. Background Technology

[0002] Guidance systems are core components of missiles and spacecraft. There are two main methods for evaluating their performance: one is to obtain data from actual target practice or flight tests, and then analyze and evaluate the system's performance based on this data; the other is to simulate the actual flight environment of the missile or spacecraft, using simulation equipment to test and evaluate various performance indicators of the guidance system on the ground, checking its operational status and tracking accuracy. The first method, due to the increasing complexity and cost of aerospace products, has become increasingly expensive, making experimental costs increasingly high. Therefore, this method is only used as a final means of evaluating navigation system performance. The second method, due to its low cost, repeatability, and high safety, has become the primary method for evaluating aerospace equipment.

[0003] A three-axis simulation turntable is a key piece of equipment in a hardware-in-the-loop flight simulation test system. It can realistically simulate various three-degree-of-freedom attitudes of an aircraft and its navigation and guidance system under laboratory conditions, reproducing its dynamic characteristics during motion. Through simulation experiments, the performance of the aircraft's sensors, guidance and control systems, and various actuators is tested, experimental data is acquired, and problems in the design are detected and identified. Continuous optimization and improvement are then carried out to meet the overall design performance requirements. This provides various reference bases for the improvement and redesign of various aircraft. The quality of its performance directly affects the reliability and confidence level of the simulation experiments.

[0004] The three-axis flight simulation turntable used in microwave anechoic chambers is primarily used for radar-guided, anti-radiation, microwave-guided, and millimeter-wave-guided seekers. The function of a microwave anechoic chamber is to provide an electromagnetic wave propagation space within a laboratory. One end of the anechoic chamber houses the antenna array of a radio frequency target simulator, while the other end contains a three-axis turntable simulating the spatial angular motion of a missile. Other areas house the radiating antennas of a radar signal environment simulator. Therefore, to avoid the turntable's influence on the echo signal, the main structural features of the three-axis flight simulation turntable for microwave anechoic chambers are a large field of view, ideally ±70° or more, and a large electromagnetic quiet zone, meaning there must be no metal materials reflecting electromagnetic waves near the seeker antenna array. This makes the structure of this type of flight simulation turntable significantly different from that of an optical seeker simulation turntable, increasing the difficulty of design and engineering implementation. In specific design, the front end of the turntable frame, drive components, and other parts is located behind the seeker antenna array to reduce the impact of electromagnetic reflection from the turntable on the seeker. Therefore, researching a three-axis flight simulation turntable suitable for radio frequency simulation under laboratory conditions has significant practical implications. Summary of the Invention

[0005] The purpose of this invention is to provide a simulation turntable that simulates the three-dimensional attitude of seekers of various types, such as radar guidance, anti-radiation, microwave guidance, and millimeter-wave guidance, in flight under ground conditions, and to test their working status in flight.

[0006] This invention comprises a base assembly, a rolling shaft system assembly, a pitch shaft system assembly, and a yaw shaft system assembly. The rolling shaft system assembly is supported on the pitch frame 14, the pitch shaft system assembly is fixed to the ship-shaped yaw frame 27, and the yaw shaft system assembly is fixed to the vertical base 1 within the base assembly.

[0007] The base assembly includes a hollow casting of a vertical base 1, and two vertical support plates 2 on the rear side of the vertical base 1 and a support base plate 3 on the bottom surface of the vertical base 1.

[0008] The rolling shaft system assembly mainly includes a rolling hollow shaft 4, a rolling frame 5, a rolling torque motor 6, a rolling bearing 7, a rolling limit moving block 8, a rolling limit stationary block 9, an inductive synchronizer 10, and a phototube 11. The rear end face of the rolling hollow shaft 4 has a pre-drilled threaded hole 13 and is installed in the rolling frame 5 through the rolling bearing 7. The stator of the rolling torque motor 6 is fixed on the rolling frame 5, the rotor of the rolling torque motor 6 is fixed on the rolling hollow shaft 4, the rolling limit moving block 8 is fixed on the rotor of the rolling torque motor 6, the rolling limit stationary block 9 is fixed on the stator of the rolling torque motor 6, and the inductive synchronizer 10 and the phototube 11 are installed on the rolling frame 5.

[0009] The pitch axis assembly is a bilaterally symmetrical structure, mainly comprising a pitch frame 14, a pitch frame trunnion 15, a trunnion bearing 16, a pitch encoder 17, a pitch torque motor mount 18, a pitch torque motor 19, a pitch torque motor shaft 20, a pitch torque motor shaft bearing 21, a pitch torque motor shaft trunnion 22, a pitch connecting rod 23, a torsion spring 24, a pitch positive angle limiting block 25, and a pitch positive angle limiting moving block 26. The pitch frame 14, with its double-sided trunnion structure, is mounted on both sides of the boat-shaped yaw frame 27 via the pitch frame trunnion 15 and trunnion bearing 16. The pitch torque motor mount 18 is fixed to the upper side of the yaw frame 27, and the pitch torque motor 19 is fixed to the pitch torque motor mount 18. The shaft 20 is mounted in the pitch torque motor seat 18 via the pitch torque motor shaft bearing 21. The pitch torque motor shaft lug 22 is fixed at both ends of the pitch torque motor shaft 20. The pitch linkage 23 connects the pitch torque motor shaft lug 22 and the pitch frame 14 via the hinge bearing 38 to form a four-bar linkage. The torsion spring 24 is sleeved on the pitch torque motor shaft 20. The two ends of the torsion spring 24 are respectively connected to the pitch torque motor seat 18 and the pitch torque motor shaft lug 22. The pitch encoder 17 is mounted on the right trunnion of the pitch frame 14. The pitch positive angle mechanical limit device includes a pitch positive angle limit moving block 26 mounted on the pitch frame 14 and a pitch positive angle limit fixed block 25 mounted inside the yaw frame 27.

[0010] The yaw shaft system assembly has a symmetrical structure and mainly includes a ship-shaped yaw frame 27, an upper yaw torque motor base 28, a lower yaw torque motor base 12, a yaw torque motor 29, a yaw shaft 30, a yaw shaft bearing 31, and a yaw encoder 32. The yaw torque motor base 28 is fixed on the vertical base 1. The yaw shaft 30, which is fixed at two positions on the upper and lower parts of the yaw frame 27, is installed in the upper yaw torque motor base 28 and the lower yaw torque motor base 12 respectively through the yaw shaft bearing 31. The yaw encoder 32 is installed on the upper end face of the yaw shaft 30.

[0011] The working principle of this invention is as follows: the yaw frame 27 fixed on the vertical base 1 rotates around the z-axis, the pitch frame 11 fixed on the yaw frame 27 rotates around the y-axis, and the rolling hollow shaft 4 fixed on the pitch frame 11 rotates around the x-axis. The combined motion of the various frames simulates the three-dimensional attitude of a seeker head in flight, such as radar guidance, anti-radiation, microwave guidance, and millimeter-wave guidance.

[0012] The beneficial effects of this invention are as follows:

[0013] The three-axis flight simulation turntable used in the microwave anechoic chamber can be used to test and evaluate the performance indicators of various types of seekers, such as radar guidance, anti-radiation, microwave guidance, and millimeter-wave guidance, on the ground. It can simulate the seeker's search for moving targets and its guidance process, realize semi-physical simulation tests of guidance systems, shorten the development cycle of aircraft and the research of guidance methods, and reduce development costs.

[0014] In response to the special working environment of microwave anechoic chambers, the vertical base, boat-shaped yaw axis assembly, four-bar pitch motion mechanism, and preload spring proposed in this invention can avoid the influence of the turntable on the echo signal and expand the field of view. The turntable has a compact structure, high overall rigidity, convenient installation and debugging, and a wide range of test piece sizes and weights. Attached Figure Description

[0015] Figure 1 This is an overall structural outline drawing of the present invention. Figure 2 This is a structural diagram of the rolling shaft system of the present invention. Figure 3 This is a front view of the pitch axis transmission mechanism of the present invention. Figure 4 This is a left view of the pitch axis transmission mechanism of the present invention. Figure 5 This is a top view of the pitch axis system of the present invention. Figure 6 This is a schematic diagram of the pitch angle mechanical limit of the present invention. Figure 7 This is a schematic diagram of the pitch negative angle mechanical limit of the present invention. Figure 8 This is a front view of the yaw shaft system structure of the present invention. Figure 9 This is a left view of the yaw shaft system structure of the present invention. Figure 10 This is a schematic diagram of the mechanical limiting of the yaw shaft system of the present invention. Detailed Implementation

[0016] Combination Figures 1-10 This implementation method is described below.

[0017] The pitch axis system of the turntable of this invention uses a parallel four-bar linkage for transmission, which reduces the influence of the pitch motor on the field of view and has the characteristic of a large field of view.

[0018] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 8 , Figure 9 The three-axis flight simulation turntable for microwave anechoic chambers includes a base assembly, a roll axis assembly, a pitch axis assembly, and a yaw axis assembly, wherein:

[0019] The base assembly, specifically the vertical base 1, is primarily used to mount the upper yaw torque motor mount 28 and the lower yaw torque motor mount 12. The precision of the vertical base 1 directly affects the precision of the yaw axis, thus affecting the non-intersection and non-perpendicularity of the three axes. To also absorb vibration, a high-precision cast iron platform is used. To improve the rigidity and stability of the vertical base 1, a support base plate 3 is installed on the bottom surface, and a vertical support plate 2 is installed on the rear side. The yaw torque motor mount 12, which is close to the ground, is also equipped with a foot support plate 33.

[0020] The rolling shaft system assembly includes a rolling hollow shaft 4, a rolling frame 5, a rolling torque motor 6, a rolling bearing 7, a rolling limit moving block 8, a rolling limit stationary block 9, an inductive synchronizer 10, and a phototube 11. The rolling hollow shaft 4 is mounted within the rolling frame 5 via the rolling bearing 7. The stator of the rolling torque motor 6 is fixed to the rolling frame 5, and the rotor of the rolling torque motor 6 is fixed to the rolling hollow shaft 4. To reduce the rotational inertia of the rolling shaft system, improve control performance, and ensure the rigidity and strength requirements of the rolling shaft system, the rolling hollow shaft 4 and the rolling frame 5 are made of 7075 forged ultra-hard aluminum to meet their strength and weight requirements. A threaded hole 13 is pre-drilled on the rear end face of the rolling hollow shaft 4, and the load is mounted from the rear end face. The rolling bearing 7 is a crossed roller bearing, which can simultaneously constrain five degrees of freedom other than rotation along the load axis, and has high rotational accuracy. The rolling torque motor 6 is an AC permanent magnet brushless torque motor, and the rolling angle measuring element is a circular induction synchronizer 10. The induction synchronizer 10 and the phototube 11 are mounted on the rolling frame 5. In this embodiment, the rolling direction movement adopts mechanical and photoelectric limits, with a mechanical limit angle of ±120° and a photoelectric limit angle of ±95°. (Reference) Figure 2 The rolling mechanical limiting device consists of a rolling limiting fixed block 9 and a rolling limiting moving block 8. The rolling limiting moving block 8 is fixed on the rotor of the rolling torque motor 6, and the rolling limiting fixed block 9 is fixed on the stator of the rolling torque motor 6.

[0021] The pitch axis assembly is a left-right symmetrical structure, mainly including a pitch frame 14, a pitch frame trunnion 15, a trunnion bearing 16, a pitch encoder 17, a pitch torque motor mount 18, a pitch torque motor 19, a pitch torque motor shaft 20, a pitch torque motor shaft bearing 21, a pitch torque motor shaft trunnion 22, a pitch connecting rod 23, a torsion spring 24, a pitch positive angle limiting block 25, and a pitch positive angle limiting moving block 26. The axis of the pitch frame trunnion 15 is parallel to the axis of the pitch torque motor shaft 20 and lies within the plane determined by the yaw axis and the pitch axis. The pitch torque motor drives the pitch frame 14 to achieve pitch movement through two sets of parallel four-bar linkages. The rotation angle of the pitch frame 14 is equal to the rotation angle of the pitch torque motor. The pitch frame 14 with double-sided ear-like structures is mounted on both sides of the yaw frame 27 via the pitch frame trunnion 15 and trunnion bearing 16. The pitch axis support uses angular contact ball bearings. (See [reference]) Figure 5During installation, the preload applied to the trunnion bearing 16 is confined within the pitch axis system and does not transmit force to the pitch frame 14. By selecting an appropriate thickness for the connecting shims, deformation of the pitch frame 14 can be avoided. The pitch frame 14 adopts a hollow annular structure and is made of ZL114A material. The rolling shaft assembly is located on the rear side of the plane formed by the pitch axis and the yaw axis, which can reduce the reflection interference of structural components to microwave signals. The pitch frame trunnions 15 are connected to both sides of the pitch frame 14. The pitch torque motor mount 18 is fixed to the upper side of the yaw frame 27. The pitch torque motor 19 is fixed to the pitch torque motor mount 18. The pitch torque motor shaft 20 is mounted in the pitch torque motor mount 18 via the pitch torque motor shaft bearing 21. The pitch torque motor shaft lug 22 is fixed to both ends of the pitch torque motor shaft 20 via expansion sleeves 35. The pitch linkage 23 connects the pitch torque motor shaft lug 22 and the pitch frame 14 via hinge bearings 38 to form a four-bar linkage. This structure avoids the influence of the pitch motor on the field of view. Furthermore, since the pitch torque motor is symmetrical about the yaw axis, the rotational inertia of the yaw axis system is reduced. A torsion spring 24 is fitted onto the pitch torque motor shaft 20, with both ends connected to the pitch torque motor mount 18 and the pitch torque motor shaft lug 22, respectively. This torsion spring 24 can reduce the zero-position off-center load, lighten the load on the zero-position bracket 36, and the preload of the torsion spring 24 helps eliminate rotational backlash. The pitch encoder 17 is mounted on the right trunnion of the pitch frame 14. Reference Figure 6 The pitch positive angle mechanical limit device includes a pitch positive angle mechanical limit moving block 26 installed on the pitch frame 14 and a pitch positive angle mechanical limit stationary block 25 installed inside the yaw frame 27; refer to Figure 7 The pitch negative angle mechanical limit is achieved by the pitch torque motor shaft lug 22 and the yaw frame 27. Two pitch frame mechanical zero positioning devices 34, which can rotate around their own axes, are installed on the inner side of the turntable vertical base 1 to achieve mechanical zeroing.

[0022] The yaw shaft system assembly has a symmetrical structure and mainly includes a ship-shaped yaw frame 27, an upper yaw torque motor base 28, a lower yaw torque motor base 12, a yaw torque motor 29, a yaw shaft 30, a yaw shaft bearing 31, a yaw encoder 32, a yaw mechanical limit moving block 36, and a yaw mechanical limit stationary block 37. To achieve a high stiffness-to-weight ratio, the yaw frame 27 is designed as a thin-walled box structure and is cast using advanced casting technology. During casting, sand-leaking holes are left on the reinforcing ribs inside the yaw frame 27. The yaw torque motor base 28 is fixed on the vertical base 1. Since the torque required for the movement of the yaw frame 27 is large and the vertical span of the yaw frame 27 is large, if a single-sided drive is used, the yaw frame 27 may experience large torsional deformation, and the structural size of a single torque motor will be too large, making it difficult to manufacture and assemble. This invention uses two identical yaw torque motors 29 to drive the yaw frame 27 synchronously on the upper and lower sides. The upper yaw torque motor base 28 and the lower yaw torque motor base 12 are machined using the same machining datum. The yaw shafts 30, fixed at two positions above and below the yaw frame 27, are respectively mounted in the upper yaw torque motor mount 28 and the lower yaw torque motor mount 12 via yaw shaft bearings 31. Angular contact ball bearings are used for support, ensuring that the preload of the yaw shaft bearings 31 is not transmitted to the yaw frame 27, thus preventing deformation of the yaw frame 27. The yaw encoder 32 is mounted on the upper end of the upper yaw shaft 30. Considering safety factors, in this example, the mechanical yaw limit angle is ±137°, and the photoelectric yaw limit angle is ±125°, as per reference. Figure 10 The yaw mechanical limit device consists of a yaw mechanical limit fixed block 37 and a yaw mechanical limit moving block 36. A set of mechanical limit devices is installed on the upper and lower sides of the yaw frame 27 to prevent unilateral torsional deformation of the yaw frame 27.

Claims

1. A three-axis flight simulation turntable for a microwave anechoic chamber, characterized in that: It consists of a base assembly, a rolling shaft system assembly, a pitch shaft system assembly, and a yaw shaft system assembly. The rolling shaft system assembly is supported on the pitch frame (14), the pitch shaft system assembly is fixed to the ship-shaped yaw frame (27), and the yaw shaft system assembly is fixed to the vertical base (1) in the base assembly. The base assembly includes a hollow casting of a vertical base (1), and two vertical support plates (2) on the rear side of the vertical base (1) and a support base plate (3) on the bottom surface of the vertical base (1). The rolling shaft system assembly mainly includes a rolling hollow shaft (4), a rolling frame (5), a rolling torque motor (6), a rolling bearing (7), a rolling limit moving block (8), a rolling limit fixed block (9), an inductive synchronizer (10), and a phototube (11). The rear end face of the rolling hollow shaft (4) is reserved with a connecting threaded hole (13), and it is installed in the rolling frame (5) through the rolling bearing (7). The stator of the rolling torque motor (6) is fixed on the rolling frame (5), the rotor of the rolling torque motor (6) is fixed on the rolling hollow shaft (4), the rolling limit moving block (8) is fixed on the rotor of the rolling torque motor (6), the rolling limit fixed block (9) is fixed on the stator of the rolling torque motor (6), and the inductive synchronizer (10) and the phototube (11) are installed on the rolling frame (5). The pitch axis assembly is a symmetrical structure, mainly including a pitch frame (14), a pitch frame trunnion (15), a trunnion bearing (16), a pitch encoder (17), a pitch torque motor mount (18), a pitch torque motor (19), a pitch torque motor shaft (20), a pitch torque motor shaft bearing (21), a pitch torque motor shaft trunnion (22), a pitch linkage (23), a torsion spring (24), a pitch positive angle limiting block (25), and a pitch positive angle limiting moving block (26). The pitch frame (14) with ear-like structures on both sides is installed on both sides of the yaw frame (27) through the pitch frame trunnion (15) and the trunnion bearing (16). The pitch torque motor mount (18) is fixed to the upper side of the yaw frame (27), and the pitch torque motor (19) is fixed on the pitch torque motor mount (18). The shaft (20) is installed in the pitch torque motor seat (18) through the pitch torque motor shaft bearing (21). The pitch torque motor shaft trunnion (22) is fixed at both ends of the pitch torque motor shaft (20). The pitch linkage (23) is connected to the pitch torque motor shaft trunnion (22) and the pitch frame (14) through the hinge bearing (38) to form a four-bar linkage. The torsion spring (24) is sleeved on the pitch torque motor shaft (20). The two ends of the torsion spring (24) are respectively connected to the pitch torque motor seat (18) and the pitch torque motor shaft trunnion (22). The pitch encoder (17) is installed on the right trunnion of the pitch frame (14). The pitch positive angle mechanical limit device includes a pitch positive angle limit moving block (26) installed on the pitch frame (14) and a pitch positive angle limit fixed block (25) installed inside the yaw frame (27). The yaw shaft system assembly is a symmetrical structure, mainly including a ship-shaped yaw frame (27), an upper yaw torque motor base (28), a lower yaw torque motor base (12), a yaw torque motor (29), a yaw shaft (30), a yaw shaft bearing (31), and a yaw encoder (32). The upper yaw torque motor base (28) and the lower yaw torque motor base (12) are fixed on the vertical base (1). The yaw shaft (30), which is fixed at two positions on the upper and lower parts of the yaw frame (27), is installed in the upper yaw torque motor base (28) and the lower yaw torque motor base (12) respectively through the yaw shaft bearing (31). The yaw encoder (32) is installed on the upper end face of the yaw shaft (30).

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